1. Field of the Invention
The present invention relates to a silver halide photographic light-sensitive material, and more particularly to a silver halide photographic light-sensitive material capable of forming a dye image whose yellow dye is remarkably improved on the resistance to light.
2. Description of the Prior Art
Of silver halide photographic light-sensitive materials (hereinafter referred to as photographic light-sensitive materials), in the black-and-white photographic light-sensitive material, the image formed therefrom is generally of matallic silver. In recent years, however, a silver-saving promotion has been taking place in an effort to cope with the shortage of silver resources and to reduce the cost of photographic light-sensitive materials. One of measures for solving this problem is the application of the color photographic technique that reproduces a neutral tone by mixing yellow, magenta and cyan dyes instead of using metallic silver.
In the field of color photographic techniques, it is already known that, for example, a coupler-containing photographic light-sensitive material, after being exposed to light, is processed in a color developer bath containing an aromatic primary amine-type color developing agent, thereby forming a dye image. Of the couplers used in the technique, the yellow dye image-forming coupler (hereinafter referred to as yellow coupler) has an active methylene radical useful for the formation of an yellow dye by the coupling reaction thereof with the oxidized product of an aromatic primary amine-type color developing agent. If the active methylene is unsubstituted (i.e., active site-unsubstituted-type yellow coupler), the coupler, because it requires 4 molecules of silver halide for the formation of its dye in a color developing reaction, is called a 4-equivalent coupler. On the other hand, it is also known that the same dye as in the unsubstituted-type coupler can also be formed from a coupler wherein one of the hydrogen atoms of the active methylene radical thereof is substituted by such a substituent component as a halogen atom, i.e., the so-called active site-substituted-type yellow coupler. In this instance, such the substituent component as a halogen atom splits off during a color developing reaction, and the coupler can form one molecule of its dye by two molecules of the developed silver halide, so that this coupler is called a two-equivalent coupler.
As the framework of yellow couplers, benzoylacetanilides were formerly widely used, but in recent years, particularly for color paper light-sensitive materials, pivaloylacetanilides have become mostly used. The transit into pivaloylacetanilides is considered mainly due to the fact that they are superior in the resistance to light of the image formed therefrom to benzoylacetanilides. However, even the yellow dye image derived from thus improved pivaloylacetanilides still not have any sufficient resistance to light for satisfying the social demand for the image preservability (the image lasting properties).
As the technique of improving the resistance to light of such the yellow dye image there are widely used such a method that, because the yellow dye image is inferior in the resistance particularly to the rays in the ultraviolet region, for the purpose of removing the ultraviolet rays, an ultraviolet absorbing agent is incorporated into the interlayer or the like of a photographic light-sensitive material. As the ultraviolet absorbing agent for this purpose there are known those 2-(2'-hydroxyphenyl)benzotriazole-type compounds as described in U.S. Pat. No. 3,253,921, Japanese Patent Examined Publication Nos. 10466/1961, 5496/1973 and 4157/1973, and Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 87326/1975. However, when any of these ultraviolet absorbing agents is used by being dispersed into a color photographic light-sensitive material, the agent not only has the disadvantage that because of its low solubility in organic solvents it is deposited into crystals to adversely affect the manufacturing process and photographic characteristics of the light-sensitive material, but, although useful for the protection from ultraviolet rays, is ineffective at all on the prevention of possible discoloration (same meaning of fading) by the light in the visible ray region, so that the addition of the agent exceeding a certain amount is practically meaningless.
On the other hand, there are also known the method for improving the resistance to light of the foregoing dye by rendering an antidiscoloration agent present under the environment of the formed dye, and as the antidiscoloration agent there are proposed the uses of bisphenols as disclosed in Japanese Patent Examined Publication Nos. 31256/1973 and 31625/1973; of 6-hydroxychromans as in U.S. Pat. Nos. 3,432,300 and 2,574,627; of 6,6'-dihydroxy-2,2'-disspirochromans as in Japanese Patent Examined Publication No. 20977/1974; of hydroquinone derivatives as in Japanese Patent Examined Publication No. 24257/1981; and of 4-hydroxybenzoate compounds as in Japanese Patent O.P.I. Publication No. 48535/1979. However, these compounds certainly have good effects on the improvement of the light resistance of magenta dyes, but has no effect at all on the yellow dye image, and on the contrary accelerate the light discoloration of the yellow dye. Japanese Patent O.P.I. Publication No. 65954/1980 proposes the presence of hindered amine-type compounds in the environment of the formed dye, but these compounds are so less soluble in organic solvents as to be deposited to adversely affect the manufacturing process of as well as the photographic characteristics of the light-sensitive material. Japanese Patent O.P.I. Publication No. 103551/1980 proposes a method for improving the resistance to light of an yellow dye image by the use in combination of a slightly-water-soluble hight-boiling organic solvent and a pivaloyl-type yellow coupler, but the method has the disadvantage that the gamma, as one of the sensitometric characteristics, becomes lowered.
Further, it is also well-known that the image preservability of a formed yellow dye image differs depending on the kind of generally used high-boiling organic solvents (having a boiling point of not less than 175.degree. C.). Japanese Patent O.P.I. Publication No. 119922/1979 proposes the use in combination of an yellow coupler and a branched-chain alkyl phosphate-type high-boiling solvent, but the proposal is disadvantageous in respect that the light-resistance effect is extremely small.
It is therefore the status quo that any satisfactory method for improving the resistance to light of the yellow dye image of a color photographic light-sensitive material is still not found.